You’ve posted under FMOD Ex, but you’ve mentioned loading a .bank file which only exists in a FMOD Studio. I’ll give you the FMOD studio answer:

1) Add AHDSR modulation to the master track volume in Studio tool:
a) Right click on the volume knob of the master track
b) Select ‘Add Modulation’ -> ‘AHDSR’
c) Adjust the last point of the graph to change the release time.